Methods and compositions for controlling fungal and bacterial infestation of plants utilizing organic tetravalent tin compounds



United States Patent Int. Cl. A01n9/00, 21/00 US. Cl. 424-286 18 Claims ABSTRACT OF THE DISCLOSURE A process for controlling fungus and bacteria infestation of plants by applying thereto a composition consisting essentially of an emultifying agent and an organic tetravalent tin compound of the fornula:

in which R R and R are lower alkyl, phenyl, benzyl or naphthyl and R is lower alkyl, phenyl, benzyl, naphthyl chloro, lower saturated aliphatic carbonyloxy, benzoyloxy, anth-ranyloxy, salicycloxy, phenoxy, phenylmercapto or chlorophenoxy.

This invention relates to compositions suitable for application on plants and seeds. More particularly, the compositions of the present invention are useful for comhating fungus and bacteria infections in plants and seeds and have insecticidal, herbicidal, algicidal, and plant growth regulating properties. Certain of the active compounds of the compositions of the present invention have exceedingly active properties and are believed to be new compounds. This application is a continuation-in-part application of our copending application, S.N. 440,868, filed July 1, 1954.

In accordance with the present invention, fungus and bacteria infections in plants and seeds may be treated by use of the compositions wherein the active component is an organic compound of tetravalent tin of the general formula:

wherein R R R and R represent the same or different alkyl, aryl, aralkyl, haloalkyl and cyclo aliphatic radicals, any of which may be replaced up to a maximum of 3 by halogens, aliphatic and aromatic monoand dicarboxylic acid radicals, radicals of monoand polyvalent alcohols, ether alcohols, phenols and thiophenols, or halogen and nitro derivatives thereof. It has been found that compounds in which at least two of the four R-positions in the formula are filled in by the normal or secondary butyl radicals are especially recommendable for such purposes.

The following compounds are mentioned by way of example: tetraethyl stannane, tetra-n-propyl-stannane, tetra-n-butyl-stannane, tetra-sec.-butyl-stannane, tetra-nhexyl-stannane, tetra-n-dodecyl-stannane, tetra-benzylstannane, tri-n-butyl monochloro stannane, tri phenyl- 3,499,086 Patented Mar. 3, 1970 ice monochloro stannane, tri-phenyl-monoacetato-stannane, tri 11 butyl monothiophenolato stannane, tri-n-butylpentachlorophenolato stannane, tri-n-butyl-mercaptobenzothiazolato stannane, di n butyl dipentachlorophenolato stannane, di ethyl dibromo stannane, di n butyl di chloro stannane, di n butyldimethoxy stannane, di n butyl di chloroacetatostannane, di n propyl-di-paranitrophenolato-stannane, di n butyl di benzoato stannane, di phenyl dichloro stannane, di-n-butyl-di-diethyldithiocarbaminatostannane, mono-butyl-trichloro-stannane, and mono-butyltribromo-stannane.

It has been found that the above compounds possess unexpected and unobvious outstanding fungicidal and bactericidal properties with a very broad effective scope, and, when combined with a suitable carrier, are outstandingly suitable for combating fungus and bacteria infections such as caused by Peronospora, Phythophthora, Fusicladium, Botrytis, Septoria and the like. They are also very effective against Helminthosporium, Fusarium and Tilletia so that they may also be employed as seed dressing agents and as disinfectants for various grains.

The most important use, however, lies in the applica tion of the above compounds on the living plants of all kinds, e.g. potatoes, celery plants, sugar beets, wheat, rye, fruit trees, etc. In these cases care must be taken to choose compounds which, while displaying satisfactory fungicidal and bactericidal properties, do not kill the plant itself by burning the leaves or stems. For this purpose are recommended stannanes in which R R R are phenyl, naphthyl or hexyl groups, whereas R is a formiate, acetate, propionate or butyrate group. It has been found that these compounds not only do not impair the living plants but on the contrary are acting as a systemic stimulant for the growth of plants, bringing about considerable increases in harvest outputs. Thus one of the objects of the present invention is the application of said compounds to living plants which are perfectly free from any fungicidal or other infectious diseases in order to promote the plant growth and the formation of their fruit.

Other organic tin compounds recommended for the treatment of living plants comprise individuals in which one or more radicals of aliphatic hydroxy carboxylic acids or amino carboxylic acids are attached to the central tin atom, e.g. tri-isopropyl-lactato-stannane, tributyl-lactatostannane, tri-isopropyl-salicylato-stannane, dibutyldisalicylato-stannane, triphenyl-lactatostannane, diphenyl-dilactato-stannane, and the corresponding compounds with anthranilic acid and with aminobenzoic acid.

The tetravalent tin compounds, generally described above, may be prepared by known methods. The compounds containing 4 hydrocarbon radicals are prepared according to the method of L. W. Jones (Journ. Chem. Soc. London 1935, pages 39-47). From these compounds halogenated compounds are prepared according to the method of K. A. Kozeschkow (berichte der Deutchen Chem. Gesellschaft, volume 62 (1929), page 996; volume 66 (1933), page (1669) The said halogenated compounds may be reacted with the sodium salts of phenols, thiophenols, monoand dicarboxylic acids etc. according to Annalen volume 114, page 366 as well as U.S. specification 2,560.034.

In addition to the fungicidal and bactericidal properties, compositions containing organic compounds of tetravalent tin of the aforesaid type have been found to be effective as insecticidal, herbicidal and algicidal agents. Furthermore, these latter properties as well as fungicidal and bactericidal properties are considerably enhanced when at lea-st one valence of the tetravalent tin is satisfied by an organic radical known to be responsible in other compositions for fungicidal, bactericidal, insecticidal, herbicidal and/or algicidal activity.

As examples for such radicals are mentioned the radicals of (fungicidal) diethyl-dithiocarbamatic acid, ethylene bis dithiocarbamatic acid, mercaptobenzothiazol, maleic acid naphthylamide; (herbicidal) 2,4-dichlorophenoxy-acetic acid, 2,4,5-trichlorophenoxy-acetic acid; (bactericidal) p-toluene sulfamide; (algicidal) pentachlorophenolate, trichloromethyl-mercaptane; (insecticidal) dialkyl-phosphoric acid, dialkyl-thiophosphoric acid. The resulting tetravalent tin compounds including such radicals are believed to be new and, as shown by examples appearing hereinafter, have exceedingly high activities. Examples of such compounds include:

Di-n-butyl-bis-(diethyl-dithiocarbarninato) -stannane, Ethylene-bis-dithiocarbaminato-bis- (triphenyl) -stannane, Tri-n-butyl-mono-pentachlorophenolato-stannane, Tri-n-butyl- 2,4, o-trichlor-phenoxy-aceto -stannane, Di-n-propyl-di-mercaptobenzothiazolato-stannane, Tri-n-butyl- (trichloromethyl-rnercapto-di-carbathoxy) methyl-stannane, Tri-n-butyl- (p-toluol-sulfamido -stannane.

In addition to possessing fungicidal, bactericidal, insecticidal, herbicidal and algicidal properties, the organic compounds of tetravalent tin represented by the above general formula possess the property of affecting the growth of plants. Thus, in relatively low concentrations, they promote and stimulate plant growth. On the other hand, in relatively higher concentrations, they will in fact destroy the plant life. Although all such compounds are effective in growth promotion, it has been found that a certain preferred group of such compounds have particularly enhanced growth regulating effects. These compounds, each of which is believed new, include organic compounds of tetravalent tin of the above general formula having at least one substituent which is a radical known in other compounds to be effective as a plant growth regulating agent. Examples of such radicals include mercaptobenzothiozol-, diethyldithiocarbamic acid-, halogenated phenoxy acetic acid-, indolyland naphthoxy fatty acid, trichloromercaptyland other radicals. Spe cific examples appearing hereinafter well illustrate these preferred organic tetravalent tin compounds.

Insofar as the growth-regulating properties of the compounds of the present invention are concerned, when an active compound is supplied in amounts of from 0.3 to 3.0 kg. per hectare (1 acre=0.4046873 hectare), preferably 0.5 to 2.0 kg. per hectare, it stimulates the growth of plants as will be shown by specific examples appearing hereinafter. Instead of treating young and. old plant cultures by applying the material on the ground or plants per se, it is of course possible to dress the seeds by applying, depending on the type of seed and the specific active material selected, from 10 to 50 g. of active material per 100 kg. of seed.

When applying larger quantities of the aforesaid preferred plant growth-regulating materials, e.g., from 5 to 30 kg. per hectare, these tetravalent tin compounds damage the intergrowth structure of the plant to such an extent that they become malformed on further growth and eventually die off. Thus, these compounds are further useful for the control of weed growth.

According to the present invention, these compounds may be associated with a carrier in the solid state, such carriers preferably being inert substances such as siliceous limestone, finely ground fire clay, kaolin, talc, calcium carbonate, sulfite liquor wastes, methyl cellulose and the like. The compositions formed with the tin compound and the solid carriers are generally ground into a powder to be dusted While wetted with water onto the treated plant matter. The tin compounds may also be disposed in a solvent or dispensed in liquid diluents such as methanol, ethanol and the like. Again, the tin compounds may be emulsified with ionic and non-ionic substances such as fatty alcohol, sulfonates, alkyl phenols and the like.

Thus for instance the stannanes of Examples XII, XIII, XVIII may be used either in form of a powder ground together with a solid carrier such as talc, kaolin and the like and suspended in water, or in the form of an emulsion in a liquid such as benzene or acetone in the presence of an emulgator such as alkylaryl sulfonates or in the form of a solution in a solvent. In each case the concentration of the organic tin compound may be about 15, 20 or 25 percent. They may also be employed in combination with other fungicidal, bactericidal and/or insecticidal substances as dusting, spraying or fogging agents.

The percentage of active ingredient in the compositions may be varied. It is, however, necessary that the active ingredient constitute a proportion such that an effective dosage will be obtained. The active ingredient is preferably used in a percentage of at least 0.005 of the weight of the matter to be treated. Activity increases with increased concentration of the agent.

The following examples are for the purpose of illustration only and are not limiting to the scope of the present invention which is set forth in the claims:

EXAMPLE I Two hundred and fifty grams of a disinfecting agent containing 20% by weight of tetrabutyl stann-ane and parts by weight of talc were mixed with 100 kg. of rye seeds which had been strongly infected with Fusarium nivale. It was found that the Fusarium infection in the resultant grain was suppressed to between 2 and 3%. On the other hand, untreated rye seeds, used as a control, produced grain that was infected up to about 56%.

EXAMPLE II A powder having a treatment concentration of from about 0.5% to 1% which consisted of 20% by weight of -dibutyl-dichlorostannane, 60% by weight of kaolin and 20% by weight of the tarry waste products of a sulfite liquor, was sprayed on celery plants of the type available on the market. It was found that the germination of the spores of Septoria apid was completely prevented and there was no resultant infection, whereas untreated and infected plan-ts showed a strong attack by the Septoriw apii fungus.

EXAMPLE III The spores of Ba trytis cinerea were placed in a nutrient solution containing only 0.005% of suspended dibutyl diacetyl stannane. None of the spores germinated. On the other hand, untreated Bot rytis spores, used as a control, were found to germinate up to within 24 hours.

EXAMPLE IV A powder having a treatment concentration of 1% consisting of 20% by weight of diphenyl dichlonostanne, 60% by weight of precipitated calcium carbonate and 20% by weight of sulfite liquor wastes, was sprayed on potato plants infected with Phytophthora infestans. No 'Phythoph-thora infection resulted. On the other hand, simultaneously infected potato plants which were not treated with the powder showed evidence of infection within 10 days.

EXAM'PLE V Spores of Sclerotz'nia frucficola were placed in a nutrient solution containing 0.01% of dirnethoxy dibutyl stannane. It was found that the germination of the spores was completely prevented. Untreated spores, used as a control, were found to germinate within six hours.

EXAMPLE VI The spores of Macrosporiztm sarcirzz'forme were placed in a nutrient solution to which only 0.01% of diethyl dibromo stannane was added. The germination of the spores was found to be completely prevented. Untreated spores,

used as a control, were found to germinate up to 90% in a 24 hour period.

EXAMPLE VII Two hundred grams of a seed powder consisting of 7.5% by weight of tri-butyl-acetato-stannane, 0.5% by weight of white oil and 92.0% by weight of talc are thoroughly mixed with 100 kg. of wheat seed which was infected by spores of Telletia tritici. The latter mixture is then sown as usual on a field. At harvest time the wheat culture so prepared is entirely free from Tilletia tritici, whereas a Wheat culture from the same wheat seeds infected with Tilletia ,tritici but not mixed with the above mentioned seed powder showed 47.0% of wheat steams ill with T illetia tritici.

EXAMPLE VIII A solution is prepared from 10.0% by weight of monobutyl-trichloro-stannane, 50.0% by weight of ordourless petrolaturn, 5.0% ethylene chloride, 5.0% by weight of a resin of the alkyd type and 30.0% by weight of :butyl glycol. A piece of dry'pine wood was impregnated with thisrsolu-tion, dried and inoculated with Poria contigua on a nutrient substratum from malt extract and gelatine. The pine wood so treated was still after a period of 6 months entirely free from fungi, whereas an unimpregnanted piece of pine wood inoculated with the same nutrient solution of Poria contigua was in the same time totally destroyed by fungi.

EXAMPLE IX 100 cubic cms. of emulsified tri-n-biityl-mono-acetostannane was added to a water reservoir of approximately 1000 litres containing a heavy growth of algae. In the course of 14 days all algae had died. The water remained free of algae after treatment.

EXAMPLE X In a water reservoir of approximately 100 litres, a syringe was cleaned containing residual emulsified tributyl (2,4,6-trichlorophenoxyaceto) stannane. Within 3 weeks all algae died and the reservoir remained free of algae.

EXAMPLE XI as follows:

Average 7 increased Concentrayield of tion, potatoes, Treating agent percent percent Dim-butyl-diaceto-stannane 0.5 32. 5 Copper Oxychloride 0.5 13. 7 Not treated i0 The potato plants treated with di-n butyl-diaceto stannane showed weak, but distinctly recognizable changes of leaves in such a way that the leaflets were more numerous and stood essentially more crowded than the ones not treated or treated with copper oxychloride.

EXAMPLE XII Celery plants which were infected with Septoria apii were sprayed in the concentration of 0.5 with a suspension containing 20.0% tri-phenyl-mono-aceto-st an nane. The application took place four times at intervals of approximately six weeks during the period of vegetation. As a comparison, one equally large number of celery plants were similarly treated with a copper preparation and another with a mercury compound. The celery plants treated with tri-phenyl-mono-aceto+stannane showed,

during the entire time of vegetation, a richer, sparkling green color of leaves and faster growth than the other treated plants. The results of these tests were as follows:

Average Percent Average weight infection weight of the of the Concenof each leaves leaves by tration celery of each Septoria Treating Agents (percent) plant (g.) plant (g.) apii Triphenyl-monoacetostannane 0. 5 662 309 0. 75

Copper Oxychloride. 0. 5 382 135 18.

Phenyl-Hg-Acetate. 0. 5 363 142 19. 65

Untreated 285 128 75. 2

EXAMPLE XIII Increased Yield Percent of Plants Concen- No. of infected with ti'ation, Beets, Leaves, Cercorpora Treating Agents Percent Percent Percent beticola Dibutyl-bis-(ethyleneblsdithiocarbamato)- stannane H 32. 5 26. 3 17. 0

Cop er Oxychlorid 18.2 14. 6 38.0

Untreated i0 ii) 97. 0

EXAMPLE XIV Rye considerably infected with Fusarium nivale was disinfected by applying a quantity of 200 g. upon kg. of rye with a powder containing 10.0% of tri-n-propylpentachlorphenolato-stannane. A known mercury disinfect ant (phenyl-Hg-acetate) was used as a means of comparison.

-It was shown that the rye seeds disinfected with tri-npropyl-pentachlorphenolato-stannane broke through the earth three day-s earlier than the ones disinfected with the mercury disinfectant. The Fusar'ium infection amounted to only 2.5% in the rye treated with tri-npropyl-pentachlorphenolato-stannane. The rye treated with the mercury disinfectant showed a 5.4% infection. The infection in the untreated rye amounted to 87.5%.

After three weeks, the lengths of the rye sprouts were also measured. With rye treated with tri-n-propyl-pentachlorophenolato-stannane, the sprouts were 30.4% longer than the ones treated with the mercury compound.

EXAMPLE XV Percent Percent Percent Infection Minor Badly Treating Agents Free Infection Infected Tri-phenyl-(triclilormethylmen capto-di-carbathoxy) -methylstannane 100 0 0 Zinc-ethy1enebis-diothiocarbamate 95. 8 4. 2 0 Untreated 2.0 29.0 69. 0

7 EXAMPLE XVI Wheat which was considerably infected with spores of Tilleriai tritici was disinfected with a powder containing 8.0% tri-ethyl-(p-toluol-sulfamido)-stannane at a rate of 200 g. per each 100 kg. of wheat. A mercury disinfectant served as a means of comparison.

The following summarizes the average field test results for three different batches:

Infection in Percent Treating Agents a b c Tri-ethyl-(p-toluol-sultamido)stannane. 0. 3 0. 2 Phenyl-Hg-acetate 0. 2 0. 8 O. 9 Untreated 57. 3 59. 6 64. 7

EXAMPLE XVII Yield results were as follows:

Average Increase Ooncen- Yield of tration, Potatoes,

Treating Agents Percent Percent Dibutyl-diaceto-st-annane 0. 21. 3 Copper oxychloride 0.. 5 7. 5 Untreated i0 EXAMPLE XVIII Celery plants of the variety Magdeburger Markt which were free of Septoria apii and other infectious discases were sprayed in the concentration of 0.5 with a suspended in water preparation containing 20.0% triphenyl-monoaceto-stannane. Theapplication took place four times at intervals of 6 weeks during the period of vegetation. As a means of comparison, an equally large number of plants were left untreated, and an equally large number of plants were sprayed with a copper preparation (50% pure Cu) and a mercury compound in the concentration of 0.5

The harvest yield, on the average, was as follows:

Average Weight Average Concenof Each Weight of tration Celery Leaves er Treating Agents (Percent) Stalk (g.) Stalk g.)

Triphenyl-aceto-stannane 0. 5 775 484 Copper Oxychloridc- O. 5 502 342 Phenyl-Hg-Acetate 0. 5 475 334 Untreated 432 316 EXAMPLE XIX The harvest yield was as follows:

Percent Increased Tributyl-pentachlorphenolato-stannane has a noticeable effect on wheat seed germination. A composition containing 15 g. of that stannane was dusted on kg. wheat seed kernels. The so-treated wheat kernels started to swell earlier than untreated ones as well as well as kernals disinfected in the usual way with a mercury disinfectant and the formers sprouts, on the average, are 3040% longer than the latters.

However, if the same stannane is sprayed in overconcentration, for example, in the form of a suspended concentrate containing 50% stannane at a quantity of 5 to 8 kg. per hectare upon germinating or young weeds 3 to 4 days before the germination of wheat, corn, beets, onions, etc., the sprouts of the weeds and the seeds just starting to swell are killed. However, this application does not effect subsequently germinating seeds.

We claim:

1. A process for controlling fungal and bacterial infestation of plants which comprises applying to the plant a fungitoxic and bacteriotoxic amount of an organic tetravalent tin compound of the formula:

wherein three members of R R R and R are each selected from the group consisting of lower alkyl, phenyl, benzyl and naphthyl and the'fourth member is selected from the group consisting of lower alkyl, phenyl, benzyl, naphthyl, chloro, lower saturated aliphatic ,carbonyloxy, benzoyloxy, anthranyloxy, salicylyloxy, phenoxy, phenylmercapto and chlorophenoxy.

2. The process of claim 1 wherein at least two of R R R and R are butyl.

3. A process as defined in claim 1 wherein the tetravalent tin compound is triphenyltin chloride.

4. A method of combatting fungi which comprises contacting the fungi with a fungitoxic amount of a compound of the formula:

wherein three members of R R R and R are each selected from the group consisting of lower alkyl, phenyl, benzyl and naphthyl and the fourth member is selected from the group consisting of lower alkyl, phenyl, benzyl, naphthyl, chloro, lower saturated aliphatic carbonyloxy, benzoyloxy, anthranyloxy, salicylyloxy, phenoxy, phenylmercapto and chlorophenoxy.

5. A method of combatting bacteria which comprises contacting the bacteria with a bacteriotoxic amount of a compound of the formula:

Sn R3/ \R4 wherein three members of R R R and R are each selected from the group consisting of lower alkyl, phenyl, benzyl and naphthyl and the fourth member is selected from the group consisting of lower alkyl, phenyl, benzyl, naphthyl, chloro, lower saturated aliphatic carbonyloxy, benzoyloxy, anthranyloxy, salicylyloxy, phenoxy, phenylmercapto and chlorophenoxy.

6. A method of combatting fungi which comprises contacting the fungi with a fungitoxic amount of a tetravalent tin compound selected from the group consisting of dialkyl-, trialkyl-, diaryland triaryltin salts of a monocarboxylic acid.

7. A method as defined in claim 6 wherein the tetravalent tin compound is a dialkyl-, trialkyl-, diarylor triaryltin acetate.

8. A method as defined in claim 6 wherein the tetravalent tin compound is triphenyltin acetate.

9. A method for controlling fungi which comprises treating matter susceptible to infestation by said organisms with a fungitoxic amount of a compound having the wherein R is selected from the group consisting of alkyl and aryl and wherein R and R" constitute the anionic portion,

/R, -s o N a member of the group consisting of the thiocarbamic acid radical and a derivative of the thiocarbamic acid radical, and wherein a is an integer from 1 to 3.

10. A method for controlling fungi which comprises treating matter susceptible to infestation by said organisms with a fungitoxic amount of a compound having the formula RaS,[SCN

wherein R is selected from the group consisting of alkyl and aryl, R is selected from the group consisting of hydrogen and alkyl, R is alkyl and a is an integer from 1 to 3.

11. A method for controlling fungi which comprises treating matter susceptible to infestation by said organisms with a fungitoxic amount of a compound having the formula R3SI1S|GNHR'NHh]S-SI1R3 s wherein R is selected from the group consisting of alkyl and aryl and R is alkylene.

12. A method for destroying fungi which comprises treating matter infested by said fungi with a fungitoxic amount of a compound having the formula wherein R is a member selected from the group consisting of alkyl and aryl, wherein anion is a member selected from the group consisting of the dithiocarbamic acid wherein three members of R R R and R are each selected from the group consisting of lower alkyl, phenyl, benzyl and naphthyl and the fourth member is selected from the group consisting of lower alkyl, phenyl, benzyl, naphthyl, chloro, lower saturated aliphatic carbonyloxy, benzoyloxy, anthranyloxy, salicylyloxy, phenoxy, phenylmercapto and chlorphenoxy.

15. The process of claim 14 wherein at least two of R R R and R are butyl.

16. A disinfectant composition comprising an emulsifying agent and a fungicidally and bactericidally effective amount of tetrabutyl tin.

17. A disinfectant composition comprising an emulsifying agent and a fungicidally and bactericidally effective amount of triphenyltin acetate.

18. A disinfectant composition comprising an emulsifying agent and a fungicidally and bactericidally effective amount of triphenyltin chloride.

References Cited UNITED STATES PATENTS 1,744,633 1/1930 Hartmann et a1. 117138.5 2,278,965 4/1942 Peski et al. 260-429.7 2,580,473 1/ 1952 Sowa et al 167-22 XR 2,507,030 5/1950 Lynch 260-429.?

FOREIGN PATENTS 68,578 9/ 1951 Netherlands.

OTHER REFERENCES Guthrie et al.: North American Veterinarian, vol. 22,

January 1941, pp. 22-24, 167/531 Van der Kerk, J. Appl. Chem, vol. 4, June 4, 1954, pp. 314-319.

ALBERT T. MEYERS, Primary Examiner V. D. TURNER, Assistant Examiner US. Cl. X.R. 7l-97; 424288 

